Today, only a small percentage of the containers that are employed by the cargo transportation industry to transport goods in international commerce are examined or inspected for contraband when they enter a country on a highway or through a port of entry such as an airport, seaport, or rail port. Such inspection is often conducted by inspectors who physically open the containers and visually (and/or manually) inspect items within the containers. Alternatively, specially trained dogs may sometimes be employed to inspect and, potentially, detect items such as drugs or explosives. Such inspection practices are manpower intensive and take a substantial amount of time per container, thereby making it cost prohibitive to inspect a high percentage of the number of containers that enter a country.
Due to recent terrorist activities and because such a small percentage of the containers are inspected, there is heightened concerned among citizens and government officials alike that terrorists may place nuclear bombs, “dirty” bombs, biological or chemical agents, or other weapons of mass destruction in such containers in order to smuggle them into a country for subsequent use against the citizenry. As a consequence, a number of vendors are developing non-intrusive inspection systems for such containers. Some of the vendors have based their systems on airport baggage scanning systems. Unfortunately, such non-intrusive inspection systems suffer from many difficulties, including that many of the systems do not produce multiple views of the objects present from multiple directions. Also, many of the systems do not provide for the discrimination or identification of materials found in objects present in a container, thereby making the detection of explosives, nuclear materials, and, generally, certain weapons of mass destruction impossible.
Other vendors have developed non-intrusive inspection systems that provide for the discrimination or identification of materials found in containers. However, such systems may be “fooled” by placing items containing different elements in an orientation relative to one another such that the combination of the different elements appears, to such systems, as a different and, possibly, non-harmful element. For example, a first item containing uranium may be positioned with a second item containing cobalt immediately behind the first item. To such material-discriminating non-intrusive inspection systems, the items may appear, together, as a single item containing the non-harmful element, lead. Thus, such material-discriminating non-intrusive inspection systems are not capable of detecting many harmful elements that may be present in containers.
Therefore, there exists in the industry, a need for a non-intrusive inspection system for containers, including apparatuses and methods, that enables the discrimination of materials within such containers independent of their placement and/or orientation relative to one another, and that addresses the above-described, and other, problems, difficulties, and/or shortcomings of current systems.